The invention relates to a reactor for entrained-flow gasification of different solid and liquid fuels using an oxidizing agent containing free oxygen under normal or raised pressure up to 8 MPa. In this case solid fuels comprise pulverized coals of various degrees of coalification, petroleum coke, and other grindable solids having a calorific value greater than 7 MJ/Nm3. Liquid fuels comprise oils, oil-solid suspensions or water-solid suspensions such as coal water slurries, for example. In the field of gas generation from solid fuels, autothermic entrained-flow gasification has been known for many years. In this case the ratio of fuel to oxygen-containing gasification agent is selected such that temperatures higher than the melting point of the ash are reached. The ash is then fused into liquid clinker which, with the gasification gas or separately, leaves the gasification chamber and is then directly or indirectly cooled. Such an apparatus is disclosed in DE 197 18 131 A1.
A detailed description of such a gasification reactor equipped with a cooling screen is given in J. Carl et al, NOELL-KONVERSIONSVERFAHREN, EF-Verlag für Energie-und Umwelttechnik GmbH 1996, pages 32-33. The design described therein includes a cooling screen, consisting of cooling tubes that are welded in a gastight manner, within a pressure vessel. This cooling screen is supported on an intermediate floor, and can extend freely upward. This ensures that, when different temperatures and consequential length changes occur as a result of start and stop processes, no mechanical stresses can occur which could possibly result in destruction. In order to achieve this, there is not a permanent connection at the top end of the cooling screen, but a gap between the cooling screen collar and the flange of the burner, allowing freedom of movement. In order to prevent gasification gas from flowing behind the cooling screen gap when pressure fluctuations occur in the system, the cooling screen gap is purged using a dry gas that is free of condensate and oxygen. Despite the purging it is evident in practice that gasification gas does flow behind, resulting in corrosion on the rear side of the cooling screen or on the pressure shell. This can lead to operating failures and even destruction of the cooling screen or of the pressure shell.